1. Field of Invention
The present invention relates to a touch panel. More particularly, the present invention relates to an optical sensor-type touch panel.
2. Description of Related Art
As the competition in the market of consumer electronics is getting more and more intense, the electronic devices equipped with touch panel are also getting popular. Currently, mainstream techniques in manufacturing touch panels include, among the others, resistor-type and capacitor-type touch panels; nowadays, however, optical-type touch panels also appear to be promising.
Optical-type touch panels utilize an optical detector to detect a touch on the touch panel. Generally, an optical-type touch panel has a pair of camera modules respectively disposed at two corners thereof. The camera modules can detect the shadow caused by a hand, a finger, or a stylus, and therefore determine the touch position on the panel.
In view of the foregoing, the accuracy and sensitivity of the optical-type touch panels would be severely jeopardized if the position and focal point of the camera module were not carefully calibrated. However, the calibration process for the complicated camera module is quite burdensome, and the results of the calibration are often unsatisfactory.